This invention generally relates to a mixing apparatus and a related mixing method. More particularly, the present invention relates to a mixing apparatus for mixing liquid and solid constituents of a substance to a homogenous liquid/solids mixture and to a related method of mixing a substance including liquid and solid constituents.
Many industrial processes require raw materials in the form of solids and liquid mixtures that tend to separate into solids and liquid constituents when stored or transported. For example, mixtures, such as calcium carbonate in water or clay water slurries, are extremely difficult to transport and store because dense solid materials settle on the bottom of storage containers during transportation and/or storage. When the container is drained, the liquid portion of the mixture is readily removed, but a portion of the solid sediment remains in the storage container. Thus, it is difficult to completely unload all of the solid material.
Calcium carbonate exemplifies a substance used as a component in the manufacture of many common household and medical products from antacids to toothpaste. Additionally, the paper industry uses this material as a substitute for wood pulp paper filler to eliminate the need for unnecessary destruction of forestry. Calcium carbonate is a fine powder substance that is normally mixed with water to create a solid and liquid suspension that is relatively easy to handle for transport in railroad tank cars or tank trucks. Because of the great demand for the end products produced by these industries, extremely large quantities of calcium carbonate must be transported.
While the liquid/solids mixture is within the tank of a transportation or storage device, the solids settle in the liquid and gradually form sediment on the bottom of the tank. This solid sediment is extremely difficult to remove from the tank when the tank is unloaded. The retention of solids in the bottom of the tank poses numerous disadvantages. First, the solids/liquid ratio of the removed mixture is reduced by the retained solids. Secondly, the backhaul of a mobile tank to pick up another load requires unnecessary rehauling of the solids back to the original pickup point, making the tank heavier and wasting fuel. Additionally, the build-up of solids reduces the capacity of the tank so that each subsequent refill of the tank includes less and less volume. Therefore it is desirous to remove substantially all of the settled solid material along with the liquid when the mixture is unloaded. This removal process can be extremely time consuming and expensive.
By way of another example, the invention may be used in the waste industry for mixing solid and liquid constituents of waste products. The invention can be used for example, to blend organic waste having a BTU value (such as K-waste, paint waste, coal tar, or other burnable materials) before it is off-load and burned at an incinerator or cement kiln.